The method of placing the terminals of the conventional electric supplying switch lock into the terminal seat is to extend the two terminals through the bottom of said terminal seat and extrude each terminal in an arc shape on the top face of the terminal seat. Contact is made by the use of larger hemisphere-shaped contact points in the two ends of a conducting bar which is placed on a rotary seat to contact, simultaneously, the arc extruded points at the bottom end of the two terminals. Alternatively, the surface of the bottom end of the two terminals is shaped into a concave hemisphere to match the hemisphere-shaped points on the ends of the conducting bar. Of the abovementioned two methods, the electrical contact in the former is completely a single point contact, but the electrical contact of the latter is a surface to surface contact. In theory, the latter is better than the former, but in fact, in application, the size and shape of the terminals are impossible to make into the ideal form. There, the actual electrical contact becomes a point or several points contact. In the basic science of electricity, resistance R=V/I wherein resistance R=K/A (A is the smallest cross sectional area of closed circuit, K is any constant).
As known, the smaller the cross sectional area of a closed circuit becomes, the lower the rated voltage of the circuit will become. The resistance will also become larger, increasing the circuit load.
In the basic structure of the lock body of the conventional electric supplying switch lock, the rod of the lock core, the seat of the lock pin, the lock pin, and the braking sheet are made separately and then combined together to form a lock body in which the lock core is placed in the lock case. This kind of structure possesses a large quantity of elements, therefore, its cost is high, and the assembly is very complicated and easily malfunctions because of an error in assembly or a dimensional error in a single element.